Angle around in the end (6)
I believe the answer is:
finish
'the end' is the definition.
(I've seen this in another clue)
'angle around in' is the wordplay.
'angle' becomes 'fish' (synonyms).
'around' indicates putting letters inside.
'fish' placed around 'in' is 'FINISH'.
(Other definitions for finish that I've seen before include "'End, close (6)'" , "Culminate" , "Patina" , "perfection" , "surface texture" .)